From: Mathias Krause <minipli@googlemail.com>
Date: Sun, 7 Apr 2013 01:51:56 +0000 (+0000)
Subject: llc: Fix missing msg_namelen update in llc_ui_recvmsg()
X-Git-Tag: v2.6.32.61~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f52780225b1707e51b67123eb13b21c500b9997;p=people%2Fms%2Flinux.git

llc: Fix missing msg_namelen update in llc_ui_recvmsg()

[ Upstream commit c77a4b9cffb6215a15196ec499490d116dfad181 ]

For stream sockets the code misses to update the msg_namelen member
to 0 and therefore makes net/socket.c leak the local, uninitialized
sockaddr_storage variable to userland -- 128 bytes of kernel stack
memory. The msg_namelen update is also missing for datagram sockets
in case the socket is shutting down during receive.

Fix both issues by setting msg_namelen to 0 early. It will be
updated later if we're going to fill the msg_name member.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 606b6adac1ca..8a814a59fed1 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -674,6 +674,8 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 	int target;	/* Read at least this many bytes */
 	long timeo;
 
+	msg->msg_namelen = 0;
+
 	lock_sock(sk);
 	copied = -ENOTCONN;
 	if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))